Filtering taking FOREVER

[vidocq]

Not new to brewing or to the filtration unit I’m using, but I’m dumbfounded.

Using an all glass (w/ stainless steel filter disk) filtration unit and 90mm Durapore hydrophilic membrane filter. I can normally filter a liter of cottonseed oil solution in about 3 hours.

however the last several batches I’ve made over the course of a few months have taken 9-15 hours or, in one case, more. I’ve properly cleaned the glassware and stainless steel mesh disk, which leaves (to me) only the filters left as the possible issue.

before I go spend another $300 on filters, I wanted to get some opinions on what other issues this extreme slowing in filtration time could be from...

 

[Christiefresh1]

I use a Small heat lamp, like for a reptile. It warms up the liquid and filters through so good. Obviously need a vacuum pump too. I filtered some test 400 yesterday and it took about 2 hours, but my deca 300 only took about 15-20 do u recon the filter may have blown on the deca? Or does deca usually filter quickly?